[Click for large view.] Author and blogger Matt Alt writes from Japan:
Ah, Seventies Japan! A Sharp Abacus-Calculator. Owned by Frederik Schodt, Japanese manga expert and all around great guy. (His book "Manga! Manga! The World of Japanese Comics" is THE must-read on the topic). Abacuses were widely used throughout Japan up until fairly recently (the 1990s or so) and there are still a handful of schools out there who teach the techniques. "These aba-calcs were really used by people who wanted the best of both worlds," he told me.